A system and method for restricting movement between the shell structure and core structure of an additively manufactured ceramic mold.

Abstract

A method for manufacturing ceramic molds and ceramic molds are provided. [Solution] The method includes the step of additively manufacturing a ceramic mold 100 using a liquid ceramic photopolymer by using an additive manufacturing system. The ceramic mold comprises a core structure 104 and a shell structure 102. A cavity 110 is defined between the core structure and the shell structure, adapted to define the shape of a cast part. The shell structure defines a plurality of shell openings. The method further includes the step of passing each pin of a plurality of pins 108 through a first shell opening of the plurality of shell openings and beyond a portion of the cavity into one of the second shell openings of the plurality of shell openings, or bringing it into contact with the core structure.

Description

Technical Field

[0001] The present disclosure generally relates to systems and methods for restricting movement between a shell structure and a core structure of an additively manufactured ceramic mold during firing of the additively manufactured ceramic mold.

Background Art

[0002] Turbine buckets or turbine blades, such as those used in gas turbine engines, aircraft engines, and / or steam turbines, can be formed, for example, using casting processes and forging processes. Conventionally, a mold is formed of a ceramic material and includes an outer ceramic shell having an inner surface defining a cavity, and one or more ceramic cores disposed within the cavity to form internal cooling passages within a casting bucket. The ceramic mold can also be formed using a lost wax casting process, and the core is first formed by ceramic injection molding into a machined core die. The formed core can then be fired at a high temperature to strengthen the core, and thereafter, the fired core is placed in another machined wax die to form a shell surrounding the core.

[0003] More recently, the manufacturing process can also form the core and shell simultaneously using an additive manufacturing process (i.e., a 3D printing process). Thereafter, the core and shell can be fired simultaneously. During firing, the additively manufactured ceramic mold may be placed in an oven where the mold is significantly heated to sinter and fuse the ceramic particles to form a dense and durable structure. However, exposure of the additively manufactured mold to high temperatures during firing can cause movement or deflection of the core relative to the shell. As a result, distortion of the cooling passages may occur, there may be a narrowing between the inner wall of the shell and the core, and / or in some cases, a core kissout, which is the condition when the core contacts the inner surface of the shell, may occur.

[0004] Therefore, systems and methods for restricting the movement of the shell and core relative to each other during firing of additively manufactured ceramic molds are desired and advantageous in the art. [Overview of the project]

[0005] The methods and ceramic molds described herein, as well as their advantages, are partially described in the following description, become apparent therefrom, or can be learned through practice of the art.

[0006] According to one embodiment, a method for manufacturing a ceramic mold is provided. The method includes the step of additively manufacturing a ceramic mold using a liquid ceramic photopolymer by using an additive manufacturing system. The ceramic mold comprises a core structure and a shell structure, each formed from the liquid ceramic photopolymer. A cavity is defined between the core structure and the shell structure. The cavity is adapted to define the shape of the cast part during casting and removal of the ceramic mold. The shell structure defines a plurality of shell openings. The method further includes the step of passing each pin of a plurality of pins through a first shell opening of the plurality of shell openings and beyond a portion of the cavity into one of the second shell openings of the plurality of shell openings, or bringing it into contact with the core structure.

[0007] According to another embodiment, a ceramic mold is provided. The ceramic mold comprises a shell structure defining a plurality of shell openings, each sized to receive a pin. The ceramic mold further comprises a core structure positioned within the shell structure. A cavity is defined between the core structure and the shell structure. The cavity is adapted to define the shape of the cast part during casting and removal of the ceramic mold.

[0008] The features, aspects, and advantages of this method and ceramic mold will be better understood by referring to the following description and the appended claims. The appended drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments of the art and, together with the description in the specification, help to illustrate the principles of the art.

[0009] A complete and effective disclosure of the Method and the Ceramic Mold, including the best mode for manufacturing and using the System and Method, intended for those skilled in the art, is described herein with reference to the accompanying drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a turbomachinery according to an embodiment of the present disclosure. [Figure 2] This is a partially fractured perspective view of a cast part (such as a turbine part) according to an embodiment of the present disclosure. [Figure 3] This figure shows a ceramic mold for producing cast parts (such as the cast parts shown in Figure 2) according to embodiments of the present disclosure. [Figure 4] This is a perspective view of a device for performing a series of steps in a method sequence for additive manufacturing of ceramic molds, such as direct light processing (DLP), according to various aspects of the present disclosure. [Figure 5] This is a cross-sectional view of a ceramic mold into which multiple pins are inserted, according to an embodiment of the present disclosure. [Figure 6] This is a cross-sectional view of a ceramic mold into which multiple pins are inserted, according to an embodiment of the present disclosure. [Figure 7] This is a cross-sectional view of a portion of a ceramic mold according to an embodiment of the present disclosure. [Figure 8] This is a cross-sectional view of a ceramic mold into which a plurality of plugs are inserted, according to an aspect of the present disclosure. [Figure 9] This is a flowchart of a method for manufacturing a ceramic mold according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] Embodiments of the method and ceramic mold of the present invention are described in detail here, one or more of which are shown in the drawings. Each example is provided for illustrative purposes of the present art and is not intended to limit the present art. In fact, it will be apparent to those skilled in the art that modifications and changes can be made in the present art without departing from the scope or spirit of the claimed art. For example, features illustrated or described as part of one embodiment can also be used in conjunction with another embodiment to bring about further embodiments. For this reason, this disclosure is intended to include modifications and changes that fall within the scope of the appended claims and their equivalents.

[0012] The term “exemplary” is used herein to mean “serving as an example, case, or illustration.” Not all implementations described herein as “exemplary” should be construed as necessarily preferable or advantageous to other implementations. Furthermore, unless specifically identified, all embodiments described herein should be considered illustrative.

[0013] In the detailed description, numerals and letters are used to refer to features of the drawings. Similar or identical reference numerals in the drawings and description are used to refer to similar or identical parts of the invention. As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of any individual component.

[0014] The term "fluid" can be a gas or a liquid. The term "fluid communication" means that a fluid can connect between specified regions.

[0015] As used herein, the terms “upstream” (or “forward”) and “downstream” (or “backward”) refer to the relative direction of fluid flow in a fluid path. For example, “upstream” refers to the direction from which the fluid has flowed, and “downstream” refers to the direction in which the fluid has flowed. However, as used herein, the terms “upstream” and “downstream” may also refer to the flow of electricity. The term “radially” refers to a relative direction that is substantially perpendicular to the axial centerline of a particular component; the term “axially” refers to a relative direction that is substantially parallel and / or coaxial with the axial centerline of a particular component; and the term “circumferentially” refers to a relative direction that extends around the axial centerline of a particular component.

[0016] Approximate terms such as “about,” “approximately,” “generally,” and “substantially” are not limited to the exact value specified. In at least some cases, the approximation may also refer to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the components and / or system. For example, the approximation may also refer to being within a margin of 1, 2, 4, 5, 10, 15, or 20 percent at any of the endpoints defining the individual value, range of value, and / or range of value. When used in the context of angles or directions, such terms include a range of plus or minus 10 degrees from the stated angle or direction. For example, “nearly perpendicular” includes any direction within 10 degrees from perpendicular, such as clockwise or counterclockwise.

[0017] Terms such as “combined,” “fixed,” and “attached” refer to both direct combination, fixation, or attachment, as well as indirect combination, fixation, or attachment via one or more intermediate components or features, unless otherwise specified herein. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variations thereof are intended to encompass non-exclusive inclusion. For example, a process, method, article, or apparatus that includes an enumeration of features is not necessarily limited to those features alone, but may include other features not expressly enumerated, or other features specific to such process, method, article, or apparatus. Furthermore, unless expressly stated otherwise, “or” refers to a comprehensive OR and not an exclusive OR. For example, condition A or B is satisfied by one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0018] Here, and throughout the entirety of the specification and claims, limitations on scope are combined and replaced, and unless the context and wording specifically indicate otherwise, such scope is identified and includes all sub-scopes contained therein. For example, all scopes disclosed herein include endpoints, which are independently combinable with respect to one another.

[0019] Referring now to the drawings, FIG. 1 shows a schematic view of one embodiment of a turbomachine, which in the illustrated embodiment is a gas turbine 10. Although industrial or land-based gas turbine engines are shown and described herein, the present disclosure is not limited to industrial or land-based gas turbine engines unless specifically stated otherwise in the claims. For example, the inventions described herein may be used in any type of turbomachine, including but not limited to steam turbines, aircraft gas turbines, or marine gas turbines.

[0020] As shown in FIG. 1, gas turbine engine 10 generally includes a compressor section 12. Compressor section 12 includes a compressor 14. Compressor section 12 includes an inlet 16 disposed at the upstream end of gas turbine 10. Gas turbine 10 further includes a combustion section 18 in which one or more combustors 20 are disposed downstream of compressor section 12. Gas turbine 10 further includes a turbine section 22 (i.e., an expansion turbine) downstream of combustion section 18. Shaft 24 extends generally axially through gas turbine engine 10 and couples compressor section 12 and turbine section 22.

[0021] Compressor section 12 can generally include a plurality of rotor disks 21 and a plurality of rotor blades 23 extending radially outwardly from each rotor disk 21 and connected to each rotor disk. Each rotor disk 21 can be coupled to or form a forward portion of shaft 24 extending through compressor section 12. The rotor blades 23 of compressor section 12 can include turbomachine airfoils defining an airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading edge and the trailing edge). Further, compressor section 12 includes stator vanes 19 disposed between rotor blades 23. Stator vanes 19 can extend from and be coupled to compressor casing 11.

[0022] The turbine section 22 can generally include a plurality of rotor disks 27 and a plurality of rotor blades 28 that extend radially outward from each rotor disk 27 and are interconnected to each rotor disk. Each rotor disk 27 can be coupled to or form a rear portion of a shaft 24 that extends through the turbine section 22. The turbine section 22 further includes an outer casing 32 that circumferentially surrounds the rear portion of the shaft 24 and the rotor blades 28. The turbine section 22 can include stator vanes or fixed nozzles 26 that extend radially inward from the outer casing 32. The rotor blades 28 and the stator vanes 26 can be arranged alternately in steps along the axial centerline 30 of the gas turbine 10. Both the rotor blades 28 and the stator vanes 26 can include turbomachinery airfoils that define an airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls that extend between the leading edge and the trailing edge).

[0023] During operation, ambient air or other working fluid is drawn into the inlet 16 of the compressor 14 and gradually compressed to supply compressed air 35 to the combustion section 18. The compressed air 35 flows into the combustion section 18 and is mixed with fuel to form a combustible mixture. The combustible mixture is burned in the combustion chamber 25 of the combustor 20, thereby generating combustion gases 41 that flow from the combustion chamber 25 to the turbine section 22. Energy (kinetic and / or thermal) is transferred from the combustion gases 41 to the rotor blades 28, rotating the shaft 24 to generate mechanical work. The used combustion gases 41 (also referred to as "exhaust gases") exit the turbine section 22 and flow through the exhaust diffuser 34 over a plurality of struts or main airfoils 43 disposed within the exhaust diffuser 34.

[0024] The gas turbine engine 10 can define a cylindrical coordinate system having an axial direction A that extends along the axial centerline 30, a radial direction R that is perpendicular to the axial centerline 30, and a circumferential direction C that extends around the axial centerline 30.

[0025] Figure 2 shows a partial fractured perspective view of an exemplary cast part 45, such as a turbine component (e.g., a rotor blade 50 or stator vane). The rotor blade 50 may be a rotor blade 23 located in the compressor section 12, or a rotor blade 28 located in the turbine section 22, as described above with reference to Figure 1. As shown in Figure 2, the rotor blade 50 generally comprises a shank 37 and an airfoil 40 extending outward from the shank 37. For example, the shank 37 may comprise a mounting section 38 and a platform 42, and the airfoil 40 may extend radially R from the platform 42. The platform 42 generally functions as a radially inward boundary to the gas flowing through the gas turbine engine 10 (e.g., air flowing through the compressor section 12, as shown in Figure 1, or hot gas 41 flowing through the hot gas path of the turbine section 22). The platform 42 extends along the axial direction A from a front surface 84 to a rear surface 82. As shown in Figure 2, the mounting portion 38 of the shank 37 may extend radially inward from the platform 42 and may have a root structure such as a dovetail joint configured to interconnect or fix the rotor blade 50 to the rotor disks 21, 27 (Figure 1). In exemplary embodiments, the rotor blade 50 may be a turbine rotor blade (such as the rotor blade 28 described above with reference to Figure 1) that can benefit from this cooling circuit.

[0026] The airfoil section 40 comprises a positive pressure sidewall 44 and an opposing negative pressure sidewall 46. The positive pressure sidewall 44 and the negative pressure sidewall 46 extend substantially radially outward from the platform 42, from the root 48, which can be defined at the intersection between the airfoil section 40 and the platform 42, to the tip 51 of the airfoil section 40. The positive pressure sidewall 44 connects to the negative pressure sidewall 46 at the leading edge 52 of the airfoil section 40 and the trailing edge 54 downstream of the leading edge 52, so that the airfoil section 40 extends between the leading edge 52 and the trailing edge 54. The positive pressure sidewall 44 generally includes the aerodynamically concave outer surface of the airfoil section 40. Similarly, the negative pressure sidewall 46 generally can define the aerodynamically convex outer surface of the airfoil section 40. The tip 51 is located radially opposite the root 48. Therefore, the tip 51 can generally define the radially outermost portion of the rotor blade 50 and may thus be configured to be located adjacent to a stationary shroud or seal (not shown) of the gas turbine 10. The tip 51 may include a tip cavity 66 or a tip shroud (not shown).

[0027] As shown in Figure 2, the rotor blade 50 may be at least partially hollow, and for example, the rotor blade 50 may include a defined cooling circuit 72 inside. The cooling circuit 72 may include a forward circuit 73 and a rear circuit 75. In some embodiments, the forward circuit 73 and the rear circuit 75 may be fluid-separated from each other. In other embodiments, the forward circuit 73 and the rear circuit 75 may be fluid-coupled from each other. The forward circuit 73 can be used to cool the front portion (or forward portion) of the rotor blade 50, and the rear circuit 75 can be used to cool the rear portion (or rear portion) of the rotor blade 50. The forward circuit 73 may be located between the leading edge 52 and the segmented rib 79, and the rear circuit 75 may be located between the segmented rib 79 and the trailing edge 54. Each forward circuit 73 may extend into the shank 37 and include a forward inlet passage 56A between an inlet 60 and a forward passage 90 of a plurality of forward passages 90 defined in the airfoil portion 40 in front of the segmented rib 79. Similarly, each rear circuit 75 may extend into the shank 37 and include a rear inlet passage 56B between the inlet 60 and one of the rear passages 96 defined in the airfoil portion 40 behind the segmented rib 79.

[0028] The front passage 90 and the rear passage 96 can be defined at least partially by and between a plurality of ribs 74. The ribs 74 extend partially through the cooling circuit 72 substantially along the radial direction R, as shown, for example, in Figure 2. The ribs 74 can extend entirely through the cooling circuit 72 between the positive pressure sidewall 44 and the negative pressure sidewall 46. For example, each rib 74 can terminate radially near either the root turnout or the tip turnout. The root turnout can be partially defined by a floor that defines the most radially inward boundary of the root turnout.

[0029] The coolant 58 may include a portion of the compressed air from the compressor section 12 (Figure 1) and / or steam, any other suitable gas, or other fluid for cooling the airfoil section 40. The inlet 60 may be located along the mounting section 38 of the rotor blade 50. The inlet 60 is in fluid communication with at least one of the forward circuit 73 via the forward inlet passage 56A or the rear circuit 75 via the rear inlet passage 56B.

[0030] In many embodiments, as shown in the illustration, the forward passage 90 may comprise a first forward passage 90 defined between the leading edge 52 and the rib 74, a second forward passage 90 defined between the two ribs 74, and a third forward passage 90 defined between the rib 74 and the split rib 79 (which separates the forward circuit 73 from the rear circuit 75). The third forward passage 90 extends directly from the forward inlet passage 56A. Multiple leading edge outlets 91 are defined on the leading edge 52, which can be in fluid communication with the first forward passage 90.

[0031] Similarly, the rear passage 96 may comprise a first rear passage 96 defined between the rib 74 and the split rib 79 (which separates the front circuit 73 from the rear circuit 75), a second rear passage 96 defined between the first pair of ribs 74, and a third rear passage defined between the second pair of ribs 74. The first rear passage 96 may extend directly from the rear inlet passage 56B. Furthermore, the rear circuit 75 may comprise a rear edge passage 92 defined between the rib 74 and the rear edge 54, which can be fluidly coupled to the third rear passage 96 via a plurality of holes 62 defined in the rib 74. In many embodiments, a plurality of rear edge outlets 93 are defined in the rear edge 54, thereby enabling fluid communication with the rear edge passage 92. In some embodiments (not shown), the rotor blade 50 may include a pin bank having a plurality of pins extending between a positive pressure side wall 44 and a negative pressure side wall 46 and located within a trailing edge passage 92.

[0032] Referring here to Figure 3, a ceramic mold 100 for producing cast parts (such as the cast parts 45 described above with reference to Figure 2) is shown according to various aspects of this disclosure. The ceramic mold 100 can be produced by utilizing additive manufacturing techniques. Additive manufacturing techniques may include, but are not limited to, several steps, including mold design by a CAD process, printing of the mold with ceramic slurry, mold preparation by exhaust, cleaning, and firing of the mold. However, these steps may cause stress concentration and other defects in the ceramic mold 100. This is especially true during the firing step, which may apply a considerable amount of stress to the ceramic parts and may cause cracking and dimensional inconsistencies. Figure 3 shows a ceramic mold 100 for cast parts (such as rotor blades) formed from a ceramic slurry in an additive manufacturing process.

[0033] The ceramic mold 100 may comprise a shell structure 102 and a core structure (not shown in Figure 3) disposed within the shell structure 102. The ceramic mold 100 may comprise an airfoil portion 140, a shank portion 160, and a base portion 170 (or pouring cup region). The airfoil portion 140 may comprise a leading edge segment 142, a trailing edge segment 144, a positive pressure side segment 146 extending between the leading edge segment 142 and the trailing edge segment 144, and a negative pressure side segment 148 located on the opposite side of the positive pressure side segment 146 and extending between the leading edge segment 142 and the trailing edge segment 144. In exemplary embodiments, as shown, the shell structure 102 of the ceramic mold 100 may define a plurality of shell openings 106. Each of the plurality of shell openings 106 may be sized, molded, and oriented to receive a corresponding pin 108. As described later, each pin 108 can be inserted into the corresponding shell opening 106 after the ceramic mold 100 having the shell opening 106 has been added, but before the ceramic mold 100 is fired. Each pin 108 extends through the shell opening 106 of the shell structure 102 and can contact the core structure of the ceramic mold 100. Once the pins 108 are inserted and fixed onto the shell structure 102, the ceramic mold 100 can be fired, and the pins 108 advantageously prevent relative movement between the shell structure 102 and the core structure of the ceramic mold 100, thereby maintaining the designed space between the shell structure 102 and the core structure during and after the firing of the ceramic mold 100.

[0034] As shown in Figure 3, multiple shell openings 106 can be defined in both the airfoil portion 140 and the shank portion 160 of the ceramic mold 100. For example, a first group of shell openings 106 may be defined in the airfoil portion 140 of the shell structure 102 of the ceramic mold 100, and a second group of openings 106 may be defined in the shank portion 160 of the shell structure 102 of the ceramic mold 100. In some embodiments, the first group may have more shell openings 106 than the second group (i.e., the airfoil portion 140 may define more shell openings 106 than the shank portion 160). In other embodiments, the first group may have fewer shell openings 106 than the second group (i.e., the airfoil portion 140 may define fewer shell openings 106 than the shank portion 160). The number of shell openings 106 in the first and second groups may depend on the size and complexity of the cast part (e.g., rotor blade).

[0035] Referring here to Figure 4, an additive manufacturing system 400 that may be used to produce the ceramic mold 100 discussed above with reference to Figure 3 is shown according to various aspects of this disclosure. In particular, the additive manufacturing system 400 shown in Figure 4 may be a direct light-emitting photoprocessing (DLP) system. However, other similar additive manufacturing systems may be used to produce the ceramic mold 100, and it should be understood that the present invention should not be limited to any particular type of additive manufacturing system unless specifically described in the claims. For example, in some embodiments, the system 400 may be a stereolithography (SLA) system utilizing a top-down irradiation technique that may be used to produce a one-piece core-shell mold according to the present invention.

[0036] An additive manufacturing system for producing ceramic molds comprises an optical imaging system 200 for providing a light source 205, a photosensitive medium 300 (such as a liquid ceramic photopolymer) adapted to change its state, and a control system 400 for continuously moving the optical imaging system over the photosensitive medium 300. The optical imaging system 200 can scan and / or cure a portion of the surface of the photosensitive medium 300 contained in a container 500 using an array of spatial light modulators (SLMs) 225. In an exemplary embodiment, the medium is a liquid ceramic photopolymer. As the optical imaging system 200 scans the photosensitive medium, the light source 205 illuminates a portion of the surface of the medium, causing a change in the properties of the medium (i.e., the liquid ceramic photopolymer cures, thereby transitioning from a liquid or aqueous state to a solid state). Next, the material construction platform 502 housed within the container 500 can be lowered (for example, in the Z direction), and the material recoating system 600 (shown as a wound-type drawdown bar for illustrative purposes) sweeps a uniform thickness layer of the photosensitive medium across the material construction platform 502 at high speed without interfering with previously constructed layers. Once the new photosensitive medium layer is formed, the focusing and aligning optical systems ensure that the surface of the medium is at the focal plane of the projection lens and can be fine-tuned in the Z direction as needed. Once this step is complete, the process repeats the cycle of curing the next layer and delivering new photosensitive material until the entire construction is complete.

[0037] Specifically, in an exemplary embodiment, light from a light source 205 of the optical imaging system 200, such as an ultraviolet (UV) light source, is tuned and delivered via the transmission optical system 215 and / or via the reflection optical system 220 (e.g., mirrors). The UV light source 205 is tuned and delivered onto the array of SLM 225 via the transmission optical system 215 and the reflection optical system 220.

[0038] The SLM225 array can receive a real-time video stream of CAD data slice bitmap images from the control system 400. The process control computer 405 of the control system 400 can turn on or off the corresponding pixels in the array. As described, light from the on pixels can be reflected downward and transmitted to the projection lens system 230. The projection lens 230 can transport a highly focused image corresponding to the on pixels, at a speed of several kilohertz (kHz), onto the surface 300 of the photosensitive medium in the material construction platform 502. The optical imaging system 200, comprising the light source 205, the optical system 215, the SLM array 225, and the projection lens 230, can be scanned at high speed along the X and Y axes to continuously expose and cure new areas of the photosensitive material in synchronization with the image continuously refreshed on the SLM array. Once the entire surface area of ​​the resin 300 has been scanned and exposed, the construction platform 502 can be moved downward along the negative Z-axis by the thickness of the slice layer, allowing a new photocurable material layer to be swept by the material recoating system 600. This process is repeated until the entire construction is complete.

[0039] The integrated core-shell ceramic mold of the present invention may be prepared using other alternative methods of DLP.

[0040] Referring here to Figures 5 and 6, two cross-sectional views of a ceramic mold 100 that can be manufactured using the additive manufacturing system 400 described above with reference to Figure 4 are shown according to embodiments of the present disclosure. As shown in Figures 5 and 6, the ceramic mold 100 includes a core structure 104 and a shell structure 102, each formed from a liquid ceramic photopolymer by the additive manufacturing system. The core structure 104 may be located within the shell structure 102. The core structure 104 of the ceramic mold 100 may correspond to the internal cavity of the cast part obtained when the ceramic mold is removed. For example, in an embodiment where the cast part is a rotor blade (such as the rotor blade 50 shown in Figure 2), the core structure 104 of the ceramic mold 100 may correspond to a cooling circuit 78 defined in the rotor blade 50. Similarly, the shell structure 102 of the ceramic mold 100 may correspond to the external structure of the cast part. For example, in an embodiment where the cast part is a rotor blade (such as the rotor blade 50 shown in Figure 2), the shell structure 102 of the ceramic mold 100 may correspond to the airfoil portion 40 and / or the shank 37. For example, the shell structure 102 may further comprise an airfoil portion 140 and a shank portion 160. The airfoil portion 140 may correspond to the airfoil portion 40 of the cast part 45 (Figure 2), and the shank portion 160 may correspond to the shank 37 of the cast part 45 (Figure 2).

[0041] As shown in Figures 5 and 6, a cavity 110 is defined between the core structure 104 and the shell structure 102. The cavity 110 is adapted to define the shape of the cast part 45 (Figure 2) during casting and removal of the ceramic mold 100. Furthermore, in exemplary embodiments, the ceramic mold 100 can be additively manufactured with a plurality of shell openings 106 defined in the shell structure 102 (shown in Figures 3 and 6). In exemplary embodiments, each of the plurality of shell openings 106 can be sized and oriented to receive a corresponding pin 108. As will be described later, each pin 108 can be inserted into the corresponding shell opening 106 after the ceramic mold 100 has been additively manufactured, but before the ceramic mold 100 has been fired. Each pin 108 extends through the shell opening 106 of the shell structure 102 and can contact the core structure 102 of the ceramic mold 100. Inserting the pin 108 allows the ceramic mold 100 to be fired, and the pin 108 advantageously prevents relative movement between the shell structure 102 and the core structure of the ceramic mold 100, thereby maintaining the designed space (e.g., cavity 110) between the shell structure 102 and the core structure during and after firing of the ceramic mold 100.

[0042] As shown in Figure 6, each pin of the plurality of pins 108, once inserted, extends through the corresponding shell opening 106, crosses a portion of the cavity 110, and can contact the outer surface of the core structure 104. Each pin 108 may be an elongated structure extending from a first end 107 and a second end 109. Each pin may define a cross-sectional shape 112 (Figure 5) that corresponds to the shape of the corresponding shell opening 106 into which the pin 108 is inserted. For example, as shown in Figure 5, the cross-sectional shape 112 of at least one of the plurality of pins 108 may be a polygonal cross-sectional shape 114 (e.g., rectangle, square, triangle, hexagon, or any other polygon). In some embodiments, the cross-sectional shape 112 of at least one of the plurality of pins 108 may be a circular cross-sectional shape 116 (e.g., circular, elliptical, oblong, or another round cross-sectional shape).

[0043] Referring back to Figure 5, the core structure 104 may comprise a front portion 122 and a rear portion 124. The front portion 122 may correspond to the front circuit 73 of the cast part 45 described above with reference to Figure 2, for example, during casting and removal of the cast part 45 from the ceramic mold 100. Similarly, the rear portion 124 may correspond to the rear circuit 75 of the cast part 45 described above with reference to Figure 2, for example, during casting and removal of the cast part 45 from the ceramic mold 100. The front portion 122 may comprise a front inlet portion 126 corresponding to the front inlet passage 56A (Figure 2) of the cast part 45. The rear portion 124 may comprise a rear inlet portion 128 corresponding to the rear inlet passage 56B (Figure 2) of the cast part 45. The core structure 104 may further comprise a tip cap portion 124 and a plurality of elongated connecting portions 118, 119 extending to the tip cap portion 124. The multiple elongated connecting portions 118, 119 may correspond to cooling passages 90, 96 (Figure 2) of the cast part 45. In particular, the front portion 122 may include a first set of multiple elongated connecting portions 118 extending to the tip cap portion 124. At least one of the first elongated connecting portions 118 may extend between the front inlet portion 126 and the tip cap portion 124. Similarly, the rear portion 124 may include a second set of multiple elongated connecting portions 119 extending to the tip cap portion 124. At least one of the second elongated connecting portions 119 may extend between the rear inlet portion 128 and the tip cap portion 124.

[0044] The first set of elongated connecting portions 118 may correspond to the front passage 90 (Figure 2) of the cast part 45 during casting and removal from the ceramic mold 100, for example. The second set of elongated connecting portions 119 may correspond to the rear passage 96 (Figure 2) of the cast part 45 during casting and removal from the ceramic mold 100, for example. The elongated connecting portions 118 and 119 may be elongated along the radial direction R (i.e., they may be the longest).

[0045] In many embodiments, at least two of the multiple pins 108 can contact each of the multiple elongated connecting portions 118, 119. At least two of the multiple pins 108 that are in contact with each of the elongated connecting portions 118, 119 can be aligned approximately in the radial direction R (for example, aligned within ±10% of the radial direction, or within ±25% of the radial direction).

[0046] Multiple pins 108 may comprise both shell-shell pins 132 and shell-core pins 134. Each shell-shell pin 132 may extend through a first shell opening defined in the shell structure 102, through the cavity 110, and through a second shell opening defined in the shell structure 102. Each shell-core pin 134 may extend through a shell opening defined in the shell structure 102 and through a portion of the cavity 110 to contact the core structure 104. As shown in Figure 5, each shell-core pin 134 may overlap (or intersect) with the core structure 104. In contrast, in Figure 5, each shell-shell pin 132 may overlap (or intersect) with the cavity 110 (e.g., not intersecting with the core structure 104). At least one shell-shell pin 132 may extend between the first connecting portion 118 and the second connecting portion 119. One or more shell-shell pins 132 may be positioned between the front inlet portion 126 and the rear inlet portion 128 (for example, between them in the axial direction). Furthermore, at least one shell-shell pin 132 may extend between the pair of second connecting portions 119.

[0047] As shown in Figure 6, the shell structure 102 comprises a leading edge segment 142, a trailing edge segment 144, a positive pressure side segment 146 extending between the leading edge segment 142 and the trailing edge segment 144, and a negative pressure side segment 148 located on the opposite side of the positive pressure side segment 146 and extending between the leading edge segment 142 and the trailing edge segment 144. In many embodiments, inserting a pin 108 into the shell opening 106 may involve inserting a first pin 108A of a plurality of pins 108 through the shell opening 106 defined by the positive pressure side segment 146 of the plurality of shell openings, beyond a first portion of the cavity 110, and into contact with a first point 152 of the core structure 104. Furthermore, inserting the pin 108 into the shell opening 106 may include inserting the second pin 108B of the plurality of pins 108 through the shell opening 106 defined in the negative pressure side segment 148 of the plurality of shell openings, beyond the second portion of the cavity 110, and into contact with the second point 154 of the core structure 104. In exemplary embodiments, the first pin 108A and the second pin 108B may be located in a common radial position.

[0048] Furthermore, in many embodiments, the first point 152 and the second point 154 are diametrically opposed to each other with respect to the core structure 104. For example, as shown in Figure 6, the two shell-core pins 134 can contact the elongated connecting portions 118 and 119 respectively, and the two shell-core pins 134 can be diametrically opposed to each other. By arranging the pins 108 in this manner, the designed space between the core structure 104 and the shell structure 102 is advantageously maintained during the firing of the ceramic mold 100.

[0049] Referring further to Figure 6, in many embodiments, after inserting each of the multiple pins 108, a bonding material 156 can be applied to the exposed portion of each pin of the multiple pins 108 and the shell structure 102 to bond the pins 108 to the shell structure 102. In some embodiments, the bonding material 156 may be a printed slurry (e.g., liquid ceramic photopolymer) that can be applied to the exposed portion of each pin of the multiple pins 108 and the shell structure 102. Subsequently, the printed slurry (e.g., liquid ceramic photopolymer) can be cured and solidified to fix the multiple pins 108 to the shell structure 102. In other embodiments, the bonding material 156 may be ceramic cement or another bonding material. The multiple pins 108 can be fixed to the shell structure by curing and solidifying the printed slurry, and / or by drying and solidifying the ceramic cement.

[0050] Referring here to Figure 7, a cross-sectional view of a portion of the ceramic mold 100 is shown according to an embodiment of the present disclosure. As shown, the shell structure 102 comprises an inner surface 103 and an outer surface 101. In exemplary embodiments, at least one of the plurality of pins 108 can form an oblique angle (e.g., neither parallel nor perpendicular) with respect to either the inner surface 103 or the outer surface 101. Furthermore, at least one of the plurality of pins 108 can form an oblique angle with respect to the radial direction R. Furthermore, during the casting of the cast part 45, after the liquid metal is poured into the ceramic mold 100, the liquid metal can solidify directionally along the directional solidification direction DS. At least one of the plurality of pins 108 can form an oblique angle (e.g., neither parallel nor perpendicular) with respect to the directional solidification direction DS, thereby advantageously reducing defects in the cast part 45. This is particularly advantageous when metal pins remain in the ceramic mold during casting.

[0051] Referring here to Figure 8, in some embodiments, after the ceramic mold 100 has been fired with the pins 108 in place (Figure 6), the pins 108 can be removed and the plugs 158 can be inserted into the shell openings 106. The plugs 158 may be a printed slurry (e.g., liquid ceramic photopolymer), which can be applied to each shell opening 106. Subsequently, the printed slurry (e.g., liquid ceramic photopolymer) can be cured to solidify and form the plugs 158. In other embodiments, the plugs 158 may be mold repair cement or another bonding material. In yet another embodiment, the plugs 158 may be printed or injection-molded rivets. The inner surface of the plugs 158 may be coplanar with the inner surface of the ceramic mold 100 so that the plugs 158 do not affect the shape of the resulting cast part.

[0052] Referring here to Figure 9, a flowchart of method 1300 for manufacturing a ceramic mold is shown according to an embodiment of the subject matter. Method 1300 can be carried out using an additive manufacturing system such as the additive manufacturing system 400 described herein or another preferred system. Overall, method 1300 is described herein with reference to the additive manufacturing system 400, the ceramic mold 100, and the cast part 45 described above with reference to Figures 1 to 8. However, it will be understood by those skilled in the art that the disclosed method 1300 may be used in general with any other preferred system configuration. In addition, although Figure 9 shows the steps performed in a particular order for illustrative and explanatory purposes, the methods discussed herein are not limited to any particular order or configuration unless specifically specified in the claims. Those skilled in the art will understand that by using the disclosure provided herein, various steps of the methods disclosed herein may be omitted, rearranged, combined, and / or adapted in various ways without departing from the scope of this disclosure.

[0053] Method 1300 may include a first process or route 1300A when ceramic pins are used in connection with Method 1300, and a second route or process 1300B when metal pins are used in connection with Method 1300. As shown in the figure, Method 1300 may include a step of additively manufacturing a ceramic mold having a core portion and a shell portion in (1302). Specifically, Method 1300 may include a step of additively manufacturing a ceramic mold using a liquid ceramic photopolymer by using an additive manufacturing system. In such a configuration, the ceramic mold may comprise a core structure and a shell structure, each formed from a liquid ceramic photopolymer. A cavity may be defined between the core structure and the shell structure. The cavity may be adapted to define the shape of the cast part during casting and removal of the ceramic mold. Furthermore, the ceramic mold may be additively manufactured such that the shell structure defines a plurality of shell openings.

[0054] The additive manufacturing of the ceramic mold in (1302) may include repeated steps of (a) bringing the hardened portion of the workpiece into contact with a liquid ceramic photopolymer, (b) irradiating a portion of the liquid ceramic photopolymer adjacent to the hardened portion, and (c) removing the workpiece from the unhardened liquid ceramic photopolymer. Steps (a) to (c) are repeated until the ceramic mold shown in Figure 3 is formed.

[0055] Method 1300 may further include the step of inserting each pin of a plurality of pins through a first shell opening of a plurality of shell openings and beyond a portion of the cavity into one of the second shell openings of the plurality of shell openings, or into contact with a core structure (for example, after additive manufacturing of a ceramic mold). The plurality of pins can be formed from either a ceramic material (such as silica, alumina, zirconia, or carbides) or a metallic material (such as platinum, or platinum or other non-oxidizing precious metals, or coated nickel-based or cobalt-based alloys). In a mounting embodiment utilizing ceramic pins, Method 1300 may include the step of inserting a plurality of pins formed from a ceramic material (for example, the same ceramic material as the ceramic mold, or a different ceramic material in some embodiments) into the ceramic mold (for example, through shell openings) in (1304A). In a mounting embodiment utilizing metallic pins, Method 1300 may include the step of inserting a plurality of pins formed from a metallic material into the ceramic mold (for example, through shell openings) in (1304B).

[0056] Method 1300 may further include, in (1306), a step of firing a ceramic mold having a core portion, a shell portion, and a plurality of pins in an oven to sinter and fuse the ceramic particles of the ceramic mold. Firing the ceramic mold may include controlled heating (e.g., in an oven or kiln) to strengthen the ceramic mold and enable it to withstand the high temperatures and pressures used in metal casting. Prior to firing, the ceramic mold may be dried to remove any residual moisture. Firing may include a low-temperature firing period in which the ceramic mold is gradually heated to remove any residual moisture, any binders, and additives in the mold material. Subsequently, firing may include a high-temperature firing period in which the ceramic particles are sintered and / or fused together, thereby providing a dense and durable mold. The ceramic mold may then undergo a controlled cooling process.

[0057] In an implementation embodiment of Method 1300 in which ceramic pins are used, Method 1300 may include the step of removing a plurality of pins from a ceramic mold in (1308). Specifically, if the plurality of pins are formed from a ceramic material, the Method may include the step of removing the pins after firing the ceramic mold. Subsequently, Method 1300 may include the step of closing the shell openings of the shell portion in (1310). That is, Method 1300 may include the step of inserting plugs into each of the plurality of shell openings. That is, after the ceramic mold has been fired with the pins in place, the pins can be removed and plugs can be inserted into the shell openings. The plugs may be a printed slurry (e.g., liquid ceramic photopolymer), which can be applied to each shell opening. Subsequently, the printed slurry (e.g., liquid ceramic photopolymer) can be cured to solidify the printed slurry and form the plugs. In other embodiments, the plugs may be mold repair cement or another bonding material, or a combination of repair cement and printed slurry.

[0058] Next, when using ceramic pins, Method 1300 may include, after closing the shell opening, the step of pouring liquid metal into the ceramic mold in (1312), and Method 1300 may include, in (1314), the step of solidifying the liquid metal to form a cast part. That is, after the mold is formed and the pin is removed, a cast part can be formed by pouring liquid metal into the casting mold and allowing it to solidify. The ceramic mold can be filled with a metal such as nickel, aluminum, cobalt, or an iron-based alloy, for example, INCONEL®.

[0059] In an implementation of Method 1300 in which metal pins are used, Method 1300 may include the step of leaving the multiple pins inserted in the ceramic mold after firing in (1316). Subsequently, when metal pins are used, Method 1300 may include the step of pouring liquid metal into the ceramic mold in (1318) such that the multiple pins diffuse into the liquid metal and / or alloy with it. For example, the liquid metal can be liquefied by heating the metal pins so that they mix with the liquid metal. After pouring in (1318), Method 1300 may include the step of solidifying the liquid metal in (1320) to form a cast part.

[0060] Finally, method 1300 may include the step of removing the ceramic mold from the cast part in (1322). The ceramic mold is then removed from the cast part by a combination of, for example, mechanical removal of the outer shell and leaching of the inner ceramic core. That is, after the ceramic mold has been fired, the cast part can be formed by pouring liquid metal into the casting mold and allowing it to solidify. The ceramic mold is then removed from the cast part by a combination of, for example, mechanical removal of the shell structure and leaching of the core structure. After leaching of the ceramic core-shell, the resulting casting is a turbine blade or a stator vane.

[0061] This specification discloses the present invention in its best mode and uses examples to enable those skilled in the art to carry out the invention, including the fabrication and use of any device or system, and the execution of any incorporated method. The patentable scope of the present invention is defined by the claims and may include other examples that those skilled in the art may conceive. Such other examples are within the scope of the claims if they include structural elements that are not different from the language of the claims, or equivalent structural elements that do not substantially differ from the language of the claims.

[0062] Further aspects of the present invention are provided by the subject matter of the following clauses.

[0063] A method for manufacturing a ceramic mold, the method comprising the steps of additively manufacturing a ceramic mold using a liquid ceramic photopolymer by using an additive manufacturing system, wherein the ceramic mold comprises a core structure and a shell structure, each formed from a liquid ceramic photopolymer, wherein a cavity is defined between the core structure and the shell structure, the cavity is adapted to define the shape of a cast part during casting and removal of the ceramic mold, and the shell structure defines a plurality of shell openings; and inserting each pin of a plurality of pins through a first shell opening of the plurality of shell openings and beyond a portion of the cavity into a second shell opening of the plurality of shell openings, or bringing it into contact with the core structure.

[0064] The method described above, comprising the step of joining the multiple pins to a shell structure after each pin of the multiple pins has been inserted.

[0065] The method according to any of the above provisions, wherein the step of joining a plurality of pins to a shell structure includes applying a printed slurry or ceramic cement to the exposed portion of each pin and the shell structure, and fixing the plurality of pins to the shell structure by curing the printed slurry or drying the ceramic cement.

[0066] The method according to any of the above provisions, wherein the cast parts include turbine parts.

[0067] The method according to any of the above clauses, wherein the core structure includes a plurality of elongated connectors corresponding to cooling channels in the cast part, and at least two of a plurality of pins are in contact with each of the plurality of elongated connectors.

[0068] The method according to any of the above clauses, wherein the shell structure comprises a positive pressure side segment and a negative pressure side segment opposite to the positive pressure side segment, and the method includes the steps of inserting a first pin of a plurality of pins through a shell opening defined in the positive pressure side segment of a plurality of shell openings and beyond a first portion of the cavity to contact a first point of the core structure, and inserting a second pin of a plurality of pins through a shell opening defined in the negative pressure side segment of a plurality of shell openings and beyond a second portion of the cavity to contact a second point of the core structure.

[0069] The method according to any of the above provisions, wherein the first pin and the second pin are located at a common radial position.

[0070] The method according to any of the above provisions, wherein the first point and the second point are diametrically opposed to each other with respect to the core structure.

[0071] The method according to any of the above clauses, wherein the shell structure includes an inner surface and an outer surface, and at least one of a plurality of pins forms an oblique angle with respect to one of the inner or outer surfaces.

[0072] The method according to any of the above clauses, wherein the method, after the insertion step, includes the step of firing a ceramic mold having a core structure, a shell structure, and a plurality of pins in an oven to sinter and fuse the ceramic particles of the ceramic mold.

[0073] The method according to any of the above clauses, wherein a plurality of pins are formed from a ceramic material, and the method includes the step of removing the plurality of pins from the ceramic mold after firing the ceramic mold.

[0074] The method according to any of the above clauses, wherein the method includes the step of inserting a plug into each of the shell openings after the multiple pins have been removed.

[0075] The method according to any of the above clauses, wherein the method includes the steps of pouring liquid metal into a ceramic mold after plugs have been inserted into each of the multiple shell openings, and solidifying the liquid metal to form a cast part.

[0076] The method according to any of the above clauses, wherein a plurality of pins are formed from a metal material, and the method comprises the steps of pouring liquid metal into a ceramic mold after firing the ceramic mold so that the plurality of pins diffuse into the liquid metal and alloy, and solidifying the liquid metal to form a cast part.

[0077] The method according to any of the above provisions, further comprising the step of removing a ceramic mold from a cast part.

[0078] The method according to any of the above provisions, wherein the step of removing the ceramic mold from the cast part includes a combination of mechanical force and chemical leaching.

[0079] A ceramic mold comprising a shell structure defining a plurality of shell openings, each sized, molded, and oriented to receive a pin, and a core structure disposed within the shell structure, wherein a cavity is defined between the core structure and the shell structure, and the cavity is adapted to define the shape of the cast part during casting and removal of the ceramic mold.

[0080] A ceramic mold according to any of the above clauses, further comprising a plurality of pins, each of which extends through a first shell opening of a plurality of shell openings and beyond a portion of the cavity to one of the second shell openings of the plurality of shell openings, or in contact with a core structure.

[0081] A ceramic mold as described in any of the above clauses, wherein the cast part is a turbine part. [Explanation of Symbols]

[0082] 10. Gas turbine, gas turbine engine 11. Compressor casing 12 Compressor section 14 Compressor 16 Entrance 18 Combustion section 19. State vanes 20 Combustors 21 Rotor Disc 22 Turbine section 23 Rotor Blades 24 shafts 25 Combustion chamber 26 Fixed nozzle, stator vane 27 Rotor Disc 28 rotor blades 30 Axial center line 32 Outer casing 34 Exhaust Diffuser 35 Compressed air 37 Shank 38 Mounting part 40 Airfoil 41. Combustion gases, high-temperature gases 42 platforms 43 Main wing section 44 Positive pressure sidewall 45 Cast parts 46 Negative pressure sidewall 48 Root 50 rotor blades 51 Tip 52 Leading edge 54 Trailing edge 56A Front entrance passage 56B Rear entrance passage 58 Coolant 60 Entrance 62 holes 66 Tip Cavity 72 Cooling circuit 73 Forward circuit 74 Ribs 75 Rear circuit 78 Cooling circuit 79-piece rib 82 Rear 84 Front 90 Front passage, cooling passage 91 Leading edge exit 92 Trailing edge passage 93 Trailing edge exit 96 Rear passage, cooling passage 100 ceramic molds 101 Exterior 102 Shell Structures 103 Inner self 104 Core structure, core body 106 Shell opening 107 First end 108 pins 108A First pin 108B Second pin 109 Second end 110 Cavity 112 Cross-sectional shape 114. Cross-sectional shapes of polygons 116. Circular cross-sectional shape 118 Elongated connecting section, first connecting section 119 Elongated connecting section, second connecting section 122 Front part 124 Rear part 126 Front entrance section 128 Rear entrance section 132 Shell-Shell Pin 134 Shell-Core Pins 140 Airfoil section 142 Leading edge segment 144 trailing edge segment 146 Positive pressure side segment 148 Negative pressure side segment 152 First point 154 Second point 156 Bonding materials 158 plug 160 Shank portion 170 Base part 200 Optical Imaging Systems 205 Light source 215 Transmission optical system, optical system 220 Reflective optical system 225 Spatial Light Modulators, SLMs, SLM Arrays 230 Projection Lens System, Projection Lens 300 Photosensitive media, surface (of photosensitive media), resin 400 Additive manufacturing systems, systems, and control systems 405 Process control computer 500 containers 502 Material Construction Platform 600 Material Recoating System 1300 methods 1300A First process or route 1300B Second route or process

Claims

1. A method for manufacturing a ceramic mold (100), wherein the method is A step of additively manufacturing a ceramic mold (100) using a liquid ceramic photopolymer by using an additive manufacturing system, wherein the ceramic mold (100) comprises a core structure (104) and a shell structure (102), each formed from the liquid ceramic photopolymer, a cavity (110) defined between the core structure (104) and the shell structure (102), the cavity (110) being adapted to define the shape of a cast part (45) during casting and removal of the ceramic mold (100), and the shell structure (102) defining a plurality of shell openings (106), The steps include passing each pin (108) of the plurality of pins (108) through the first shell opening (106) of the plurality of shell openings (106) and inserting it into the second shell opening (106) of the plurality of shell openings (106) beyond a portion of the cavity (110), or bringing it into contact with the core structure (104), and Methods that include...

2. The above method is performed after each of the multiple pins (108) has been inserted. The step includes joining the plurality of pins (108) to the shell structure (102), The optional step of joining the plurality of pins (108) to the shell structure (102) is: Applying printed slurry or ceramic cement to the exposed portion of each of the plurality of pins (108) and the shell structure (102), and The plurality of pins (108) are fixed to the shell structure (102) by curing the printed slurry or drying the ceramic cement. The method according to claim 1, including the method described in claim 1.

3. The method according to any one of claims 1 to 2, wherein the cast part (45) includes a turbine part.

4. The method according to any one of claims 1 to 3, wherein the core structure (104) comprises a plurality of elongated connecting portions (118) corresponding to cooling channels in the cast part (45), and at least two of the plurality of pins (108) are in contact with each of the plurality of elongated connecting portions (118).

5. The shell structure (102) comprises a positive pressure side segment (146) and a negative pressure side segment (148) on the opposite side of the positive pressure side segment (146), and the method is The steps include: passing the first pin (108A) of the plurality of pins (108) through the shell opening (106) defined in the positive pressure side segment (146) of the plurality of shell openings (106), inserting it beyond the first portion of the cavity (110), and bringing it into contact with the first point (152) of the core structure (104); The steps include passing the second pin (108B) of the plurality of pins (108) through the shell opening (106) defined in the negative pressure side segment (148) of the plurality of shell openings (106), inserting it beyond the second portion of the cavity (110), and bringing it into contact with the second point (154) of the core structure (104), The method according to any one of claims 1 to 4, including the method described in any one of claims 1 to 4.

6. The method according to claim 5, wherein the first pin (108A) and the second pin (108B) are located at a common radial position, or the first point (152) and the second point (154) are diametrically opposed to each other with respect to the core structure (104).

7. The method according to claim 1, wherein the shell structure (102) comprises an inner surface (103) and an outer surface (101), and at least one of the plurality of pins (108) forms an oblique angle with respect to one of the inner surface (103) or the outer surface (101).

8. The method according to any one of claims 1 to 7, wherein the method includes, after the insertion step, firing the ceramic mold (100) comprising the core structure (104), the shell structure (102), and the plurality of pins (108) in an oven to sinter and fuse the ceramic particles of the ceramic mold (100).

9. The plurality of pins (108) are formed from a ceramic material, and the method is performed after firing the ceramic mold (100), Steps to remove the plurality of pins (108) from the ceramic mold (100) The method according to any one of claims 1 to 8, including

10. The above method is performed after the plurality of pins (108) have been removed. The method includes the step of inserting a plug (158) into each of the plurality of shell openings (106), and optionally, after the plug (158) has been inserted into each of the plurality of shell openings (106), The steps include pouring liquid metal into the ceramic mold (100), The steps include solidifying the liquid metal to form the cast part (45) and The method according to claim 9, including the method described in claim 9.

11. The plurality of pins (108) are formed from a metal material, and the method is performed after firing the ceramic mold (100), The steps include pouring the liquid metal into the ceramic mold (100) so that the plurality of pins (108) diffuse into the liquid metal and form an alloy, The steps include solidifying the liquid metal to form the cast part (45) and The method according to any one of claims 1 to 8, including

12. The method according to claim 11, further comprising the step of removing the ceramic mold (100) from the cast part (45).

13. The method according to claim 12, wherein the step of removing the ceramic mold (100) from the cast part (45) includes a combination of mechanical force and chemical leaching.

14. A shell structure (102) defining a plurality of shell openings (106) each sized, molded, and oriented to receive a pin (108), The core structure (104) is disposed within the shell structure (102) and A ceramic mold (100) comprising a core structure (104) and a shell structure (102), wherein a cavity (110) is defined between the core structure (104) and the shell structure (102), and the cavity (110) is adapted to define the shape of a cast part (45) when the ceramic mold (100) is cast and removed.

15. The ceramic mold (100) according to claim 14, further comprising a plurality of pins (108), each of the plurality of pins (108) extending through a first shell opening (106) of the plurality of shell openings (106) and beyond a portion of the cavity (110) to one of the second shell openings (106) of the plurality of shell openings (106), or in contact with the core structure (104), and / or the cast part (45) is a turbine part.

Images